Half Price Books, Records, Magazines Inc. generates the vast majority of its sales via its 117 bricks-and-mortar stores. But that doesn’t mean it doesn’t know how to use the web to its advantage.

The seller of used and discounted books ran an e-mail campaign in February that within a week garnered it more than 36,000 new e-mail subscribers and brought nearly 14,000 consumers into its stores, says Kathy Doyle Thomas, the retailer’s executive vice president.

The e-mail campaign promoted the retailer’s Book Lovers’ Weekend event, which coincided roughly with Valentine’s Day. The retailer sent two versions of the e-mail to consumers in its e-mail database, which numbers more than 1 million, Doyle Thomas says. Half of the list received a link to a 20%-off coupon and the other half a link to a $5-off offer on a purchase of $25 or more The messages encouraged recipients to share news of the offer, and included links to spread word of the promotion on Twitter, Facebook and Pinterest.

Doyle Thomas says including the social links helped quickly expanded the reach of the deals. Although social sharing numbers weren’t immediately available, she says the offer appealed to the retailer’s customers who typically are highly passionate about books and like to talk about them. Consumers who heard about the promotion on social media had to register for Half Price Books’ e-mail list to get a link to a coupon, Doyle Thomas says.

She says nearly 14,000 people redeemed one of the coupons in stores. Consumers were much more responsive to the 20%-off coupon than the offer of $5 off a purchase of $25 or more. The 20% offer was redeemed six times more often than the $5 off offer.

“People don’t like being told they have to spend a certain amount,” she says. The retailer uses e-mail marketing services vendor ExactTarget for its e-mail campaigns. Doyle Thomas says it will use the results to help plan for future campaigns.

The purpose of the campaign was to drive consumers to the retailer’s stores. The challenge, she says, is that it wanted to create an offer that shoppers would want to share and that would encourage shoppers to drive to one of its stores to buy a book rather than go online and purchase it from Amazon.com.

It’d be easy to run coupons or discount offers often and get lots of shares and foot traffic, Doyle Thomas says. But the retailer only does so sparingly, she says, to avoid training consumers to wait for discounts. She fears consumers would just come to ignore the e-mails or only come to the stores after getting an offer.

That’s not the image the retailer—which already sells titles well below cover price—wants to project. Half Price Books only runs discounts about three times a year, Doyle Thomas says. Most of the e-mails it sends to its customer list are about store events or designed to be informational and appeal to consumers who love to read, such as an e-mail that lists 40 must-read titles.